Part Identification

[OldChrome]

There is a rather hefty vacuum line, driver's side, that has what appears to be a 'vacuum diaphragm'.

The problem - It is making a hissing sound which... pretty clearly says that it has a leak.

Here's a pic:

I've been through my Haynes manual and called local parts stores but they don't show a listing for my '93 XLT.

Are they simply generic or... are they called something else?

Thanks for any help

...

 

[the_don]

That is a one-way vacuum valve, and yes they do make a hissing sound. unless the outer case is cracked i wouldnt worry too much.

 

[OldChrome]

Thanks!